v3.10.0.1
Document and Entity Information - shares
9 Months Ended
Sep. 29, 2018
Nov. 02, 2018
Document and Entity Information    
Entity Registrant Name SPX CORP  
Entity Central Index Key 0000088205  
Document Type 10-Q  
Document Period End Date Sep. 29, 2018  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   43,392,063
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3  
Entity Emerging Growth Company false  
Entity Small Business false